[Grammar] they may be concerned about the safety of the school environment,

[ambitious-girl]

Is the punctuation of the italic sentences correct? I think we need to add a conjunction before the word in bold. I'd like to have your ideas as well.


Much of the homeschooling movement is made up of families who, for various reasons, are dissatisfied with the schools available to them. They may have a differing educational philosophy, they may be concerned about the safety of the school environment, or they may feel that the local schools cannot adequately address their children's educational needs.

source: Essential words for IELTS Barron's

 

[ambitious-girl]

Thanks RobertJ for your help.

So, how about the comma splices? Can we connect two independent clauses with only "," ?
They may have a differing educational philosophy, they may be concerned about the safety of the school environment.

 

[GoesStation]

The word "or" after the last comma is the key to this. It may be clearer if you simplify the sentence: They may have a differing educational philosophy, they may be worried, or they may feel uncertain. The model is "They may be a, they may be b, or they may be c."

 

[ambitious-girl]

The word "or" after the last comma is the key to this.

Thanks GoesStation. I got it. Such an informative information.

If we only have two sentences below, then we have "comma splices". However, when "or" is used at the last part of the sentences, it means that all sentences before are connected together, so they are no longer considered comma splices.

"They may be a, they may be b". :cross:

"They may be a, they may be b, or/and they may be c." :tick: